Re: Is my MySQL Gaining ? - Mailing list pgsql-general

If you have no control over the running postmasters, then where the
files are stored gives you no advantage at all either
for backup or security. Backing up physical files while the postmaster
running is asking for it; this is explained every three days
or so on the lists. (that should be part of some consent form for using
PG...'I acknowledge that copying physical files while
the postmaster is running is ineffective, will get me in trouble, and
promote both moral degradation and tooth decay. Please don't ask.').

As for security...the data cluster is created with 700 permissions,
owned by the postgres super-user, and the postmaster will not
even start up if the directory permissions are set otherwise.

Personally, I wouldn't trust a sysad/dba at an ISP who gave me
sufficient rights to create, say, Oracle tablespaces willy-nilly. That
would fit your
example of lazy and lax administration. (Apologies for using the 'O'
word...)

We're back into the mindset of an RDBMS being thought of as some sort
of FoxPro-on-steroids thing. That is not what Postgres, Oracle,
Sybase, etc. are.



On Dec 30, 2003, at 5:40 AM, Bret Busby wrote:

> On Tue, 30 Dec 2003, Tom Lane wrote:
>
>> Date: Tue, 30 Dec 2003 02:07:23 -0500
>> From: Tom Lane <tgl@sss.pgh.pa.us>
>> To: Bret Busby <bret@busby.net>
>> Cc: pgsql-advocay@postgresql.org, pgsql-general@postgresql.org
>> Subject: Re: [GENERAL] Is my MySQL Gaining ?
>>
>> Bret Busby <bret@busby.net> writes:
>>> Does PostgreSQL yet allow the user or programmer, to determine where
>>> the
>>> database will be stored?
>>
>> You speak as though you think that would be a good idea.
>>
>> In my mind, "where the database is stored" is not a matter for users,
>> nor for programmers, but for DBAs --- that is, the grunts who have to
>> worry about backup policies and suchlike.  This is not an issue that
>> should be exposed at the SQL-command level, and therefore it does not
>> concern either users or database programmers.
>>
>> That's not to say that we don't have work to do here.  There's
>> considerable interest in developing "tablespace" features to help the
>> DBA manage his problems.  But I absolutely will not buy into any
>> suggestion that user foo's tables must be stored in user foo's home
>> directory (even if I thought that Postgres user foo must correspond
>> to a local Unix user foo ... which I don't ...)
>>
>>             regards, tom lane
>>
>>
>
> This is where terminology becomes amusing.
>
> I meant the OS user, not the DBMS user, and I am not suggesting that
> DBMS users should be able to set where their tables are stored.
>
> All kinds of scenarios can arise; where the DBA and the developer are
> the same person, or, employed in the same department of the same
> company; where the DBA is employed by the company, and the developer is
> a contractor, or an employee of a contractor, and, as I previosuly
> mentioned, the scenario where an ISP, by hosting a web site with a
> database backend, has a database in the same holding area as is held
> all
> the databases of all of the ISP's clients who similarly have web sites
> with database backends.
>
> I would feel more confident about having a personal database "on the
> Internet"; a backend to my web site, if I knew that the database wasn't
> thrown into the same storage area as everyone of the ISP's other
> account
> holders, who also have the same DBMS database backends to their web
> sites. You never know what else is sharing the same storage area, or
> how
> safe your database is in there. It is a bit like having a cat; I would
> rather that the cat is with me, and that I know where it is, and what
> is
> happening with the cat, than having the cat locked away in a common
> room
> for all cats. Also, using that analogy, if I decide to move away with
> my
> cat, if it is with me, it is much simpler, and, cleaner, for me to
> simply pick up the cat and take it with me, than to try to find all of
> its bits, in a common room full of other cats. If I have a database
> system hosted by an ISP, and I try to move it to another ISP, surely,
> it
> would be simpler and cleaner, if I know that the database is stored in
> or under my home directory with the ISP, than having the database
> stored
> in a central repository with all of the other accounts holders'
> databases.
>
> There is also the issue of security, in the same context; I would feel
> much more secure, with a database hosted by an ISP, if I could control
> the privileges on the database directory, rather than allowing the ISP
> the control. Having been a user on various UNIX systems, I have seen
> some pretty lax security by systems administrators, and other users,
> and
> I am reminded of a senior university computing lecturer, who had the
> exam for an advanced computing unit, with such lax security that some
> students wandering through the system, found the exam, and, when they
> sat the exam, were surprisingly well prepared (no, I was not one of the
> students), resulting in all the students in the unit, having to re-sit
> the exam, and, other effects. A DBA should be able to control where a
> database is stored, and the level of security applicable to where the
> database is stored (privileges applicable to the directory, etc), and,
> as I have previously mentioned, it can occur that the DBA and the
> developer/programmer, are the same person.
>
> As an example, on a personal basis, if I ever get the number of names
> in
> my genealogy system, up to around 10,000, I would really want, if using
> a database backend (which would, I believe, be required), to have
> control over where the data is stored, so that I can easily and
> reliably
> back it up, as such data can be unreplaceable, and can take decades to
> accumulate.
>
> Similarly, for commercial databases, now that DVD's are writable,
> backing up a largish database, using OS backing up, would be much
> better, and moreso, witth the data for a database, stored where it is
> wanted.
>
> I am not sure whether it can all be done with symbolic links, to place
> PostgreSQL databases where a (OS, not DBMS) user or developer or DBA
> wants them to be stored, but I suggest that provision should exist for
> a
> person to determine where the person's (as owner of the database)
> database file(s) exist, for security, backing up, etc.
>
> --
> Bret Busby
> Armadale
> West Australia
> ..............
>
> "So once you do know what the question actually is,
>  you'll know what the answer means."
> - Deep Thought,
>   Chapter 28 of
>   "The Hitchhiker's Guide to the Galaxy:
>   A Trilogy In Four Parts",
>   written by Douglas Adams,
>   published by Pan Books, 1992
> ....................................................
>
>
> ---------------------------(end of
> broadcast)---------------------------
> TIP 1: subscribe and unsubscribe commands go to
> majordomo@postgresql.org
>
--------------------

Andrew Rawnsley
President
The Ravensfield Digital Resource Group, Ltd.
(740) 587-0114
www.ravensfield.com